Bookrack

ABSTRACT

A bookrack includes a book mounting plate for mounting an opened book to be read thereon, and the book mounting plate is supported to be capable of tilting to a left side and a right side in an opening direction of the book. A first spring member energizes the book mounting plate to tilt toward the right side, and a second spring member energizes the book mounting plate to tilt toward the left side. A structure is provided for keeping the book mounting plate in a normal position steadily under a state where energizing forces of the first and second spring members are balanced. The book mounting plate tilts to the left side or the right side due to a difference in weights between left and right spread portions of the book mounted on the book mounting plate, resisting against the energizing force from either of the first and second spring members.

FIELD OF ART

The present invention relates to a bookrack which provides easiness in reading a book containing many pages, such as an encyclopedia, a dictionary and an academic tome.

BACKGROUND OF THE INVENTION

A conventional bookrack has a book mounting plate in which a book head side thereof is situated at a higher position and a book tail side thereof is situated at a lower position, so that the conventional bookrack provides easiness in reading.

DISCLOSURE OF INVENTION Objects to be Solved

The present invention intends to solve a difficulty in reading, which a conventional bookrack is not capable of solving, due to a level difference between a left spread portion and a right spread portion of a thick book and due to a curved surface formed along a region close to a spine portion of the book.

Method to Solve the Object

In order to attain the object described above, the present invention provides a bookrack including a book mounting plate for mounting a book which is opened in order to be read thereon, and the book mounting plate is supported to be capable of tilting to a left side and a right side in an opening direction of the book. A first spring member energizes the book mounting plate to tilt toward the right side, and a second spring member energizes the book mounting plate to tilt toward the left side. A structure is provided for keeping the book mounting plate in a normal position steadily under a state where energizing forces of the first and second spring members are balanced. The bookrack is configured so that the book mounting plate tilts to the left side or the right side due to a difference in weights between a left spread portion and a right spread portion of the book which is opened and mounted on the book mounting plate, resisting against the energizing force from either of the first and second spring members.

In addition, the present invention provides a bookrack including a book mounting plate for mounting a book which is opened in order to be read thereon, and the book mounting plate is supported to be capable of tilting to the left and right side in the opening direction of the book. A first spring member energizes the book mounting plate to tilt toward the right side, and a second spring member energizes the book mounting plate to tilt toward the left side. A structure is provided for keeping the book mounting plate in a normal position steadily under a state where energizing forces of the first and second spring members are balanced. The bookrack is configured so that the book mounting plate tilts to the left side or the right side due to a difference in weights between a left spread portion and a right spread portion of the book which is opened and mounted on the book mounting plate, resisting against the energizing force from one of the first and second spring members while acceding to the energizing force from the other of the first and second spring members.

Further, the present invention provides the bookrack according to a first aspect or a second aspect, including a pair of double torsion springs disposed symmetrically as the first and second spring members. The double torsion spring includes a pair of coil portions and a book mounting plate energizing portion provided between the pair of the coil portions. When the book mounting plate tilts to the left side or the right side due to the difference of the weight between the left spread portion and the right spread portion of the book which is opened and mounted on the book mounting plate, the book mounting plate energizing portion of the first double torsion spring or the second double torsion spring is displaced in a lower direction. Thereby, the pair of the coil portions of the first double torsion spring or the second double torsion spring builds up torsion resilience. The book mounting plate is supported with the torsion resilience, being energized to tilt toward the right side or the left side.

Further, the present invention provides the bookrack according to the first aspect or the second aspect, including tension coil springs disposed symmetrically as the first and second spring members. When the book mounting plate tilts to the left side or the right side due to the difference of the weight between the left spread portion and the right spread portion of the book which is opened and mounted on the book mounting plate, the book mounting plate is supported with tensile resilience of a first tension coil spring or a second tension coil spring, being energized to tilt toward the right side or the left side.

Further, the present invention provides the bookrack, according to the first aspect or the second aspect, including a shaft for fixing the first spring member and the second spring member thereto, in order to adjust the energizing forces of the first and second spring members, and a left plate and a right plate for receiving the energizing forces. The energizing forces against the left and right plates can be increased and decreased by moving the shaft in an upper direction and the lower direction.

Effects of the Invention

As described above, in the present invention, when a thick book containing many pages is opened and mounted on a book mounting plate, the book mounting plate tilts to a left side or a right side, whichever heavier, due to a relative difference of weight (thickness) between a left spread portion and a right spread portion of the book. By tilting to the left side or the right side, a level difference caused by the difference of the thickness between the left spread portion and the right spread portion is solved. As a result, a curved surface portion formed between the thick spread portions of the book can be seen as straightforwardly as possible. Accordingly, letters, pictures and so on, printed on the curved surface portion can be read easily.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereunder, embodiments of the present invention will be explained with reference to FIGS. 1 through 6. The reference sign 1 in FIGS. 1, 3, 4, 5 and 6 is a book mounting plate for mounting a book. As shown in FIGS. 1A and 1C, the book mounting plate 1 is supported by axes 6 a and 6 b disposed in the middle of a left plate 1 a and a right plate 1 b of the book mounting plate, so that the book mounting plate is capable of tilting to a left side or a right side.

In other words, a shaft 3 stands on a central portion of a mounting base 2 and rotatably supports the book mounting plate 1 about the axes (6 a and 6 b) situated on a center line thereof extending in a front and back direction, where the book mounting plate 1 is equally divided into the left plate 1 a and the right plate 1 b.

Further, as shown in FIGS. 1(A) and 1(B), the embodiment includes a first double torsion spring 4 and a second double torsion spring 9 as a first spring member and a second spring member in the embodiment. The first double torsion spring 4 and the second double torsion spring 9 belong to a kind of torsion coil springs and are disposed symmetrically about the axes 6 a and 6 b. A configuration of the double torsion spring is shown in FIG. 2 and explanation about each of the portions thereof in the embodiment will be described later.

With reference to FIGS. 1(A) and 1(B), a relationship between the book mounting plate 1 and the first and second double torsion springs 4 and 9 will be described in detail. The first and second double torsion springs 4 and 9 include book mounting plate energizing portions 4 b and 9 b, respectively. The book mounting plate energizing portions 4 b and 9 b abut against backside surfaces of the left plate 1 a and the right plate 1 b, respectively. At this point, energizing forces of both of the double torsion springs 4 and 9 against both of the plates 1 a and 1 b are balanced. In other words, both energizing forces are in a state of zero and the book mounting plate 1 maintains a normal position.

In addition, fixing leg portions 4 c and 9 c of the first and second double torsion springs 4 and 9 are fixed by being inserted into leg portion insertion holes 3 a and 3 b. As shown in FIGS. 1, 3, 4 and 6, the leg portion insertion holes 3 a and 3 b are provided in the shaft 3.

Hereunder, configuration and each portion in the embodiment of the double torsion springs 4 and 9 will be explained in detail with reference to FIG. 2.

The first and second double torsion springs 4 and 9 include a pair of coil portions 4 a and 9 a; upward extending portions situated between the pairs of the coil portions 4 a and 9 a, and downward extending portions situated on both ends of the pair of the coil portions 4 a and 9 a, respectively. In the embodiment, the upward extending portions are utilized as book mounting plate energizing portions 4 b and 9 b, and the downward extending portions are utilized as the fixing leg portions 4 c and 9 c for fixing the double torsion springs 4 and 9.

In addition, the book mounting plate energizing portions 4 b and 9 b extend outside toward the left side and the right side respectively with a certain angle α1 as the first and second torsion springs 9 and 4 are situated at bilaterally symmetrical positions.

As shown in FIGS. 3(A) and 3(B), when a book 8 is opened and mounted on the book mounting plate 1 and there is a difference of weight (a thickness) between a left spread portion 8 a and a right spread portion 8 b of the book, the book mounting plate 1 tilts to a side the weight is heavier and the thickness is thicker, either of the left side (FIG. 3(A)) or the right side (FIG. 3(B)), resisting against an energizing force from either of the first and second double torsion springs 4 and 9.

In other words, as shown in FIG. 3(A), when the left spread portion 8 a is thicker and heavier, the book mounting plate 1 tilts to the left side. Further, the book mounting plate energizing portion 4 b of the first double torsion spring 4 is displaced toward a lower direction, thus the pair of the coil portions 4 a of the first double torsion spring 4 builds up torsion resilience. The torsion resilience supports the book mounting plate 1 tilting to the left side by energizing so as to tilt toward the right side.

Similarly, as shown in FIG. 3(B), when the right spread portion 8 b is thicker and heavier, the book mounting plate 1 tilts to the right side. Further, the book mounting plate energizing portion 9 b of the second double torsion spring 9 is displaced toward the lower direction, thus the pair of the coil portions 9 a of the second double torsion spring 9 builds up torsion resilience. The torsion resilience supports the book mounting plate 1 tilting to the right side by energizing so as to tilt toward the left side.

Therefore, a level difference L (FIG. 3( c)), normally generated by the difference of the thickness between both of the spread portions 8 a and 8 b is canceled, by tilting to the left side or the right side, as described above. As a result, a curved surface portion 8 c formed between the spread portions can be seen as straightforwardly as possible. Accordingly, letters, pictures and so on, printed on the curved surface portion can be read easily.

Further, a reference sign 11 in FIG. 4 shows one of examples of a spring energizing force adjusting member for the first and second double torsion springs 4 and 9. A spring energizing force adjusting screw 11 is placed along a recessed portion 2 a of the mounting base 2. A screw thread portion 11 a is screwed upward or downward with a rotation of a bolt head portion 11 b of the spring energizing force adjusting screw 11. Thereby the shaft 3 moves upward or downward. Accordingly, the energizing forces of the double torsion springs 4 and 9 against the left plate 1 a and the right plate 1 b of the book mounting plate 1 can be increased and decreased, respectively.

More specifically, as shown in FIG. 4(A), the book mounting plate energizing portions 4 b and 9 b of the first and second double torsion springs 4 and 9 abut against the backside surfaces of the left plate 1 a and the right plate 1 b, respectively. At this point, the energizing forces of both of the double torsion springs 4 and 9 against both of the plates 1 a and 1 b are balanced. In other words, both energizing forces are in a state of zero and the book mounting plate 1 maintains the normal position.

As shown in FIG. 4(B), as a result of rotating the bolt head portion 11 b of the spring energizing force adjusting screw 11 and the screw thread portion 11 a is screwed upward, the shaft 3 moves upward and the book mounting plate energizing portions 4 b and 9 b of the double torsion springs 4 and 9 are displaced toward the lower direction. Consequently, the pairs of the coil portions 4 a and 9 a of the double torsion springs 4 and 9 build up the torsion resilience, respectively. With the torsion resilience, the double torsion springs 4 and 9 energize the left plate 1 a and the right plate 1 b of the book mounting plate 1 so as to tilt toward the right side and the left side, respectively. At this point, the energizing forces of both of the double torsion springs 4 and 9 are balanced. That is, the energizing forces of both of the double torsion springs 4 and 9 against both of the plates 1 a and 1 b are equally increased, thereby the book mounting plate 1 maintains the normal position.

As shown in FIG. 4, the shaft 3 is not fixed on the mounting base 2 when the spring energizing force adjusting screw 11 is attached. A shaft frame 10 attached to the mounting base 2 leads the shaft 3 to move upward and downward.

FIG. 4(D) is a view showing a state when the screw thread portion 11 a of the spring energizing force adjusting screw 11 is screwed downward. FIG. 4(E) is a view showing a state when the screw thread portion 11 a of the spring energizing force adjusting screw 11 is screwed upward. In each case, there is the difference of the weight between the left spread portion 8 a and the right spread portion 8 b of the book 8 mounted on the book mounting plate 1 and the book mounting plate 1 tilts to the left side with the same inclined angle Y.

As shown in FIG. 4(E), when the screw thread portion 11 a is screwed upward, a downward displacement angle X2 of the book mounting plate energizing portion 4 b becomes larger than a downward displacement angle X1 of the book mounting plate energizing portion 4 b, which is shown in FIG. 4(D). The first double torsion spring 4 supports the left plate 1 a, energizing the left plate 1 a so as to tilt toward the right side with the energizing force larger than the force in a state the screw thread portion 11 a is screwed downward.

Though an exemplification and a detailed explanation will be omitted, the second double torsion spring 9 supports the right plate 1 b, energizing the right plate 1 b similarly, so as to tilt toward the left side with the energizing force larger than the force in a state the screw thread portion 11 a is screwed downward.

Therefore, upon providing the spring energizing force adjusting screw 11, the double torsion springs 4 and 9 can obtain the energizing forces which is more effective (stronger) when the book mounting plate 1 tilts to the left side or the right side as the book 8 mounted thereon is much heavier.

As shown in FIGS. 4(F) and 4(G), in a case that the book mounting plate 1 tilts to the left side with the screw thread portion 11 b screwed upward, the book mounting plate 1 is supported as tilting toward the left side with the energizing force of the second double torsion spring 9, resisting against the energizing force of the first double torsion spring 4 until the energizing portion 9 b of the second double torsion spring 9 recovers to a normal position 9 b′, that is, until the energizing force of the second torsion spring 9 against the right plate 1 b of the book mounting plate 1 becomes zero. Subsequently, the book mounting plate 1 is supported as tilting to the left side, resisting against the energizing force of the first torsion spring 4 as shown in FIGS. 4(G) and 4(H).

Though an exemplification and a detailed explanation will be omitted, similarly, in a case that the book mounting plate 1 tilts to the right side with the screw thread portion 11 screwed upward, the book mounting plate 1 is supported as tilting to the right side with the energizing force of the first double torsion spring 4, resisting against the energizing force of the second double torsion spring 9 until the energizing portion 4 b of the first double torsion spring 4 recovers to a normal position 4 b′, that is, until the energizing force of the first double torsion spring 4 against the left plate 1 a of the book mounting plate 1 becomes zero. Subsequently, the book mounting plate 1 is supported as tilting to the right side, resisting against the energizing force of the second double torsion spring 9.

In addition, though reference to the drawings except for some cases will be omitted, the present invention includes modified examples of the double torsion springs 4 and 9. A single torsion spring which is a kind of torsion coil springs, a compression spring, a tension coil spring, and a leaf spring can be used as the first and second spring members. The book mounting plate 1 maintains the normal position as the energizing forces of both of the spring members are balanced. When there is the difference of the weight between the left spread portion 8 a and the right spread portion 8 b of the book 8 and the book mounting plate 1 tilts to the left side or the right side, the first spring member energizes one of the right and left plates 1 a and 1 b so as to tilt toward the left side and the second spring member energizes other of the right and left plates 1 a and 1 b so as to tilt toward the right side. Thereby, the level difference L (FIG. 3( c)) generated by the difference of the thickness between the left spread portion 8 a and the right spread portion 8 b is canceled and the curved surface portion 8 c, formed along a region close to a spine portion of the spread portion which is thicker, can be seen as straightforwardly as possible.

FIG. 5 (4′ and 9′) are views showing an example in which the tension coil springs is used as the first and second spring members of the bookrack in the present invention.

Further, it is possible to prevent the book 8 from sliding in a lateral direction when the book mounting plate 1 tilts to the left side or the right side, by attaching a rubber sheet having a frictional resistance on a surface of the book mounting plate 1.

In addition, as shown in FIG. 6, the book mounting plate 1 can incline (elevation angle α2) in order to read more easily. In this case, a book longitudinal sliding prevention member 7 can be provided on a lower edge of the book mounting plate 1 so that the book does not slide in a longitudinal direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(A) is a front view of a bookrack showing an embodiment of the present invention; (B) is a sectional view showing the embodiment of the bookrack; (C) is a side view showing the embodiment of the bookrack;

FIG. 2(A) is a perspective view showing a first double torsion spring; (B) is a front view showing the first and a second double torsion spring; (C) is a plan view showing the first and second double torsion springs;

FIG. 3(A) is a sectional view showing a state that a book is mounted on the bookrack (weight load on a left side); (B) is a sectional view showing a state that the book is mounted on the bookrack (weight load on a right side); (C) is a front view showing the book in a state that the bookrack is not used;

FIG. 4(A) is a partial sectional view showing a state that a spring energizing force adjusting screw is provided (the spring energizing force adjusting screw is screwed downward); (B) is a partial sectional view showing a state that the spring energizing force adjusting screw is provided (the spring energizing force adjusting screw is screwed upward); (C) is a perspective view showing a shaft and a shaft frame; (D) is a partial sectional view showing a state that a book mounting plate tilts to the left side (the spring energizing force adjusting screw is screwed downward); (E) is a partial sectional view showing a state that the book mounting plate tilts to the left side (the spring energizing force adjusting screw is screwed upward); (F) is a partial sectional view showing a state that the book mounting plate maintains a normal position with the spring energizing force adjusting screw (the spring energizing force adjusting screw is screwed upward); (G) is a partial sectional view showing a state that the book mounting plate tilts to the left side (the spring energizing force adjusting screw is screwed upward and a energizing force of the second double torsion spring is zero); (H) is a partial sectional view showing a state that the book mounting plate tilts to the left side (the spring energizing force adjusting screw is screwed upward and a energizing force of the second double torsion spring is in a normal state);

FIG. 5(A) is a front view showing a state that a tension coil spring is provided; (B) is a front view showing a state that the tension coil spring is provided (tilting to the left side); and (C) is a front view showing a state that the tension coil spring is provided (tilting to the right side);

FIG. 6 is a side view showing a state that the book mounting plate has an elevation angle.

DESCRIPTION OF THE REFERENCE SYMBOLS

1 BOOK MOUNTING PLATE

1 a A LEFT PLATE OF THE BOOK MOUNTING PLATE

1 b A RIGHT PLATE OF THE BOOK MOUNTING PLATE

2 MOUNTING BASE

2 a RECESSED PORTION

3 SHAFT

3 a LEG PORTION INSERTION HOLE OF FIRST DOUBLE TORSION SPRING

3 b LEG PORTION INSERTION HOLE OF SECOND DOUBLE TORSION SPRING

4 FIRST DOUBLE TORSION SPRING

4 a PAIR OF COIL PORTIONS OF FIRST DOUBLE TORSION SPRING

4 b BOOK MOUNTING PLATE ENERGIZING PORTION OF FIRST DOUBLE TORSION SPRING

4 b′ BOOK MOUNTING PLATE ENERGIZING PORTION OF FIRST DOUBLE TORSION SPRING (NORMAL POSITION)

4 c FIXING LEG PORTION OF FIRST DOUBLE TORSION SPRING

4′ FIRST TEISION COIL SPRING

6 AXIS

6 a AXIS (FRONT SIDE)

6 b AXIS (BACK SIDE)

7 BOOK LONGITUDINAL SLIDING PREVENTION MEMBER

8 BOOK

8 a LEFT SPREAD PORTION OF BOOK

8 b RIGHT SPREAD PORTION OF BOOK

8 c CURVED PORTION OF BOOK

9 SECOND DOUBLE TORSION SPRING

9 a PAIR OF COIL PORTIONS OF SECOND DOUBLE TORSION SPRING

9 b BOOK MOUNTING PLATE ENERGIZING PORTION OF SECOND DOUBLE TORSION SPRING

9 b′ BOOK MOUNTING PLATE ENERGIZING PORTION OF SECOND DOUBLE TORSION SPRING (NORMAL POSITION)

9 c FIXING LEG PORTION OF SECOND DOUBLE TORSION SPRING

9′ SECOND TEISION COIL SPRING

10 SHAFT FRAME

11 SPRING ENERGIZING FORCE ADJUSTING SCREW

11 a SCREW THREAD PORTION

11 b BOLT HEAD PORTION

L LEVEL DIFFERENCE

α1 EXTENDING ANGLE OF BOOK MOUNTING PLATE ENERGIZING PORTION

α2 ELEVATION ANGLE OF BOOK MOUNTING PLATE

X1 DISPLACEMENT ANGLE OF BOOK MOUNTING PLATE ENERGIZING PORTION (SCREW THREAD PORTION SCREWED DOWNWARD)

X2 DISPLACEMENT ANGLE OF BOOK MOUNTING PLATE ENERGIZING PORTION (SCREW THREAD PORTION SCREWED UPWARD)

Y TILTING ANGLE OF BOOK MOUNTING PLATE (SCREW THREAD PORTION SCREWED DOWNWARD AND UPWARD) 

1. A bookrack comprising: a book mounting plate (1) for mounting a book (8) being opened in order to be read, said book mounting plate being supported to be capable of tilting to a left side or a right side in an opening direction; a first spring member for energizing the book mounting plate (1) to tilt toward the right side; and a second spring member for energizing the book mounting plate to tilt toward the left side, said first spring member and said second spring member being structured to keep the book mounting plate (1) in a normal position steadily under a state where energizing forces of the first and second spring members are balanced so that the book mounting plate (1) tilts to the left or right side by a difference of weights between a left spread portion (8 a) and a right spread portion (8 b) of the book (8) opened and mounted on the book mounting plate, resisting against the energizing force of one of the first and second spring members.
 2. A bookrack comprising: a book mounting plate (1) for mounting a book (8) being opened in order to be read, said book mounting plate being supported to be capable of tilting to a left side or a right side in an opening direction; a first spring member for energizing the book mounting plate (1) to tilt toward the right side; and a second spring member for energizing the book mounting plate to tilt toward the left side, said first spring member and said second spring member being structured to keep the book mounting plate (1) in a normal position steadily under a state where energizing forces of the first and second spring members are balanced, so that the book mounting plate (1) tilts to the left or right side by a difference of weights between a left spread portion (8 a) and a right spread portion (8 b) of the book (8) opened and mounted on the book mounting plate (1), resisting against the energizing force of one of the first and second spring members while acceding to the energizing force of the other of the first and second spring members.
 3. The bookrack according to claim 1 or claim 2, comprising a pair of double torsion springs (4, 9) disposed symmetrically as the first and second spring members, wherein said double torsion spring includes a pair of coil portions (4 a, 9 a) and a book mounting plate energizing portion (4 b, 9 b) provided between the pair of the coil portions, when the book mounting plate (1) tilts to the left side or the right side due to the difference of the weights between the left spread portion (8 a) and the right spread portion (8 b) of the book (8) mounted on the book mounting plate, the book mounting plate energizing portion (4 b, 9 b) of the first double torsion spring or the second double torsion spring (4, 9) is displaced in a lower direction and the pair of the coil portions (4 b, 9 b) of the first double torsion spring or the second double torsion spring (4, 9) builds up torsion resilience and the book mounting plate (1) is supported with the torsion resilience, being energized to tilt toward the right side or the left side.
 4. The bookrack according to claim 1 or claim 2, comprising tension coil springs (4′, 9′) disposed symmetrically as the first and second spring members, wherein the book mounting plate (1) is supported with tensile resilience of the second tension coil spring (9′) or the first tension coil spring (4′), being energized to tilt toward the right side or the left side as the book mounting plate (1) tilts to the left side or the right side due to the difference of the weights between the left spread portion (8 a) and the right spread portion (8 b) of the book (8) mounted on the book mounting plate (1).
 5. The bookrack according to claim 1 or claim 2, further comprising a shaft (3) for fixing the first spring member and the second spring member thereto, for adjusting the energizing forces of the first and second spring members; and a left plate and a right plate (1 a, 1 b) for receiving the energizing forces, wherein said shaft moves in an upper direction and a lower direction to increase and decrease the energizing forces against the left and right plates. 